Aflatoxin B1 (AFB1), a foodborne mycotoxin, has been found to be the most potent chemical hepatocarcinogen known to man. The objective of this research is to determine the metabolism and disposition of AFB1 by the rhesus monkey and the similarity between monkey and man in their responses to AFB1 as indicated by its biotransformation by human and monkey livers in vitro. In vitro and in vivo metabolites of AFB1 will be isolated, identified, and quantified to characterize the drug metabolizing activity of different species and to possibly develop a diagnostic procedure for human AF exposure. Highly radioactive AFB1 will be used as the substrate in various metabolic studies. Metabolites will be purified by thin layer chromatography and high pressure liquid chromatography and identified by mass, uv, and nmr spectrometric analyses. Their toxicity will be assessed using the chicken embryo and Salmonella-microsomal assays. BIBLIOGRAPHIC REFERENCES: Salhab, A.S., D.P.H. Hsieh. Aflatoxicol H1: A Major Metabolite of Aflatoxin B1 Produced by Human and Rhesus Monkey Livers in vitro. Research Communications In Chemical Pathology and Pharmacology, Vol. 10, No. 3, March 1975, pp. 419-431. Krieger, R.I., A.S. Salhab, J.I. Dalezios, D.P.H. Hsieh. Aflatoxin B1 Hydroxylation by Hepatic Microsomal Preparations from the Rhesus Monkey. J. Food Cosmet. Toxicol., Vol. 13, 1975, pp. 211-219.